Method and systems for bleed air supply

ABSTRACT

A method and system for an integrated ejector valve assembly is provided. The integrated ejector valve assembly includes a first valve assembly configured to control a flow of relatively lower pressure fluid from a first inlet port, a second valve assembly configured to control a flow of relatively higher pressure fluid from a second inlet port, a first actuation chamber configured to close the first valve assembly, a second actuation chamber configured to close the second valve assembly, and a third actuation chamber configured to open the second valve assembly.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a division of application Ser. No. 12/495,366, filedJun. 30, 2009 now U.S. Pat. No. 8,267,122, which is hereby incorporatedby reference in its entirety.

BACKGROUND OF THE INVENTION

The field of the invention relates generally to bleed air systems, andmore specifically, to a method and systems for an integrated ejectorvalve assembly for supplying bleed air to an aircraft.

At least some known aircraft use engine bleed air for cabinpressurization, anti-ice and other functions on the aircraft. The bleedair pressure must be reduced under most operating conditions to providea regulated air supply. Engine bleed air pressures vary greatly withengine speed and operating altitude. Engines typically have two bleedextraction ports, a low pressure (LP) port which is used wheneverpossible and a high pressure (HP) port which is used only at conditionsof high altitude and/or low engine speed when LP bleed pressure isinsufficient to supply the needs of the aircraft.

An ejector can often be beneficial using some regulated HP bleed air toboost LP flow and extracting LP flow when the LP pressure is lower thanrequired. A pressure regulating and shut-off valve controls the bleedair system pressure. An LP non-return valve (NRV) is usually provided toassure that there is no back flow from the HP bleed port to the LP bleedport. An HP pressure regulating and shut-off valve controls the flow ofair from the HP bleed port when LP air pressure is insufficient.

A typical jet engine has two bleed air extraction ports, a low pressure(LP) bleed port and a high pressure (HP) bleed port. Engine efficiencyis maximized by using LP air whenever the LP bleed port pressure isadequate. The HP bleed port is used to supply bleed air only whennecessary. It is often advantageous to extract equal bleed air flowsfrom each engine in both the LP and HP modes while controlling the bleedair system pressure.

Known bleed air systems include a pressure regulator downstream of thebleed ports that may also provide a shut-off function so they are knownas pressure regulating shut-off valves (PRSOV). The LP NRV preventsbackflow into the engine LP bleed port when the LP pressure is largerthan required bleed system pressure. A high pressure shut-off valve(SOV) is opened when LP air pressure is insufficient. In some cases,this valve is also a pressure regulating valve (HPPRSOV).

The transition from LP to HP is typically abrupt. When the LP pressureis inadequate, the HP shut-off valve (SOV), or HPPRSOV in some cases, isopened. The higher pressure from the HP part closes an LP check valve toprevent backflow. The entire flow is then supplied by the HP bleed port.In some configurations, the LP NRV and LP check valve functions areperformed by the same component.

However such systems include many components that each includes numerousparts. The individual parts must be stocked for maintenance and repairoperations and the number of components adds to the weight of theaircraft, causing a loss of efficiency.

BRIEF DESCRIPTION OF THE INVENTION

In one embodiment, an integrated ejector valve assembly includes a firstvalve assembly configured to control a flow of relatively lower pressurefluid from a first inlet port, a second valve assembly configured tocontrol a flow of relatively higher pressure fluid from a second inletport, a first actuation chamber configured to close the first valveassembly, a second actuation chamber configured to close the secondvalve assembly, and a third actuation chamber configured to open thesecond valve assembly.

In another embodiment, a method of supplying engine bleed air to anaircraft using a first integrated ejector valve assembly includescontrolling a flow of a relatively lower pressure fluid received at thefirst integrated ejector valve assembly using a first valve assembly,controlling a flow of a relatively higher pressure fluid received at thefirst integrated ejector valve assembly using a second valve assembly,and maintaining a pressure in an outlet of the first integrated ejectorvalve assembly using the controlled flow of relatively lower pressurefluid and the controlled flow of relatively higher pressure fluid.

In yet another embodiment, an aircraft system includes a first gasturbine engine including a first high pressure bleed port and a firstlow pressure bleed port, a second gas turbine engine including a secondhigh pressure bleed port and a second low pressure bleed port, and anengine bleed air header configured to channel bleed air at a selectablepressure to the aircraft. The aircraft system also includes a firstintegrated ejector valve assembly coupled in flow communication betweenthe first high pressure bleed port and first low pressure bleed port,and the engine bleed air header, a second integrated ejector valveassembly coupled in flow communication between the second high pressurebleed port and second low pressure bleed port, and the engine bleed airheader, and a controller communicatively coupled to the first integratedejector valve assembly and the second integrated ejector valve assembly,the controller configured to substantially match an output flow of thefirst integrated ejector valve assembly and the second integratedejector valve assembly.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1-3 show exemplary embodiments of the method and systems describedherein.

FIG. 1 is a schematic block diagram of an aircraft bleed air system inaccordance with an exemplary embodiment of the present invention;

FIG. 2 is a schematic block diagram of the integrated ejector valveassembly shown in FIG. 1 in accordance with an exemplary embodiment ofthe present invention; and

FIG. 3 is an isometric cross section of the integrated ejector valveassembly shown in FIG. 1 in accordance with an exemplary embodiment ofthe present invention.

DETAILED DESCRIPTION OF THE INVENTION

The following detailed description illustrates embodiments of theinvention by way of example and not by way of limitation. It iscontemplated that the invention has general application to bleed airsystems in industrial, commercial, and residential applications.

As used herein, an element or step recited in the singular and proceededwith the word “a” or “an” should be understood as not excluding pluralelements or steps, unless such exclusion is explicitly recited.Furthermore, references to “one embodiment” of the present invention arenot intended to be interpreted as excluding the existence of additionalembodiments that also incorporate the recited features.

FIG. 1 is a schematic block diagram of an aircraft bleed air system 100in accordance with an exemplary embodiment of the present invention. Inthe exemplary embodiment, aircraft bleed air system 100 includes a bleedair header 102 from which a plurality of bleed air loads 104 draw asupply of bleed air at a predetermined pressure. A pressure within bleedair header 102 is maintained within a predetermined range using one ormore bleed air control circuits including integrated ejector valveassemblies. In the exemplary embodiment, aircraft bleed air system 100includes a first bleed air control circuit 105 including a firstintegrated ejector valve assembly 106 and includes a second bleed aircontrol circuit 107 including a second integrated ejector valve assembly108. Each integrated ejector valve assembly is supplied with relativelylower pressure bleed air from a low pressure (LP) bleed port 110, 112 ofan associated gas turbine engine 114, 116 through respective supplylines 111 and 113, and supplied with higher pressure bleed air from highpressure (HP) bleed ports 120 and 122 through respective supply lines121 and 123.

The integrated ejector valve assemblies can control the downstream bleedair pressure under all operating conditions, using LP bleed airexclusively when LP pressure is sufficient and augmenting with HP flowwhen LP pressure is insufficient.

In one embodiment of the invention, valve elements within integratedejector valve assemblies 106 and 108 are controlled by an electroniccontroller 124 that includes a processor 126. In an alternativeembodiment, the valve elements are controlled using conventionalpneumatic signals. Pressure to actuate the valve elements is channeledfrom HP bleed ports 120 and 122 and is ported to the various chambers bytorque motor servo valves (not shown in FIG. 1) controlled by electronicor pneumatic controller 124 through respective signal lines 127 and 129.With this control flexibility, the valve elements can be used as flowcontrol valves, pressure regulating valves, or as shut-off valves withno hardware changes. Integrated ejector valve assemblies 106 and 108 arealso used to equalize flow between gas turbine engines 114 and 116.

In the exemplary embodiment, integrated ejector valve assemblies 106 and108 are described as flow control valves using flow signals fromdownstream flow meters 128 and 130 channeled to controller 124 throughrespective signal lines 131 and 133, that controls the position of thevalve elements, for example, but not limited to, pintle and poppetvalves positioned within integrated ejector valve assemblies 106 and108.

For illustration, assume that bleed air pressure must be maintainedbetween 30 and 40 psig. A pressure range setting of 32±2 psig isassigned for HP operation and 38±2 psig is assigned for LP operation.Note that these pressure bands do not overlap. Whenever bleed systempressure is above the HP setpoint, the HP pintle valve will be fullyclosed. Whenever the pressure is below the LP setpoint, the LP poppetvalve will be fully open. Whenever the pressure is above the LP setpointthe poppet valve will be fully closed to prevent backflow from HP bleedport 120 or 122 to LP bleed port 110 or 112, respectively.

FIG. 2 is a schematic block diagram of integrated ejector valve assembly106 or 108 (shown in FIG. 1) in accordance with an exemplary embodimentof the present invention. For ease of description, only integratedejector valve assembly 106 is described, integrated ejector valveassembly 108 being substantially identical. In the exemplary embodiment,integrated ejector valve assembly 106 includes a first valve assembly200 configured to control a flow of relatively lower pressure fluid froma first inlet port 202. First valve assembly 200 includes a valve seat204 and a valve member 206, such as, but not limited to, a poppet valve.Integrated ejector valve assembly 106 further includes a second valveassembly 208 configured to control a flow of relatively higher pressurefluid from a second inlet port 210. Second valve assembly 208 includes avalve seat 212 and a valve member 214, such as, but not limited to, apintle valve. Integrated ejector valve assembly 106 also includes afirst actuation chamber 216 configured to close first valve assembly200, a second actuation chamber 218 configured to close second valveassembly 208, and a third actuation chamber 220 configured to opensecond valve assembly 208. In the exemplary embodiment, integratedejector valve assembly 106 includes an ejector 222 configured to use theflow of relatively higher pressure fluid to facilitate increasing theflow of relatively lower pressure fluid. Second valve assembly 208acting as a throttle element controls HP flow by a pintle in the primarythroat of ejector 222. Secondary LP flow is entrained by ejector 222.

A first torque motor servo valve (not shown in FIG. 2) comprising amanifold having a plurality of passages (also not shown in FIG. 2)configured to control a pressure in first actuation chamber 216. Asecond torque motor servo valve 223 comprising a manifold 224 having aplurality of passages 226 configured to control a differential pressurebetween second actuation chamber 218 and third actuation chamber 220. Inthe exemplary embodiment, first valve assembly 200 is configured tomaintain a pressure at an outlet 228 of integrated ejector valveassembly 106 greater than a first predetermined range of pressure andsecond valve assembly 208 is configured to maintain a pressure at theoutlet of integrated ejector valve assembly 106 greater than a secondpredetermined range of pressure, wherein the first range of pressure isgreater than the second range of pressure, and wherein the first andsecond ranges do not overlap. A longitudinal axis 227 extends throughintegrated ejector valve assembly 106 from inlet 202 to outlet 228 andin various embodiments through a mixing chamber 229 in flowcommunication with outlet 228.

During operation, integrated ejector valve assembly 106 can control thedownstream bleed air pressure under all operating conditions, using LPbleed air exclusively when LP pressure is sufficient and augmenting withHP flow when LP pressure is insufficient.

The elements of integrated ejector valve assembly 106 are controlled bycontroller 124. In the exemplary embodiment, controller 124 is anelectronic controller. In an alternative embodiment, controller 124 is apneumatic controller configured to control the valve elements withpneumatic signals. Pressure to actuate first valve assembly 200 andsecond valve assembly 208 is channeled from HP bleed port 120 (shown inFIG. 1) and is ported to the various chambers by torque motor servovalve 223 controlled by controller 124. With this control flexibility,first integrated ejector valve assembly 106 and second integratedejector valve assembly 108 can be used as flow control valves, pressureregulating valves, or as shut-off valves with no hardware changes. Theejector valve can also be used to equalize flow between the engines ofmultiple engine aircraft.

In the exemplary embodiment, integrated ejector valve assemblies 106 and108 are described as flow control valves using flow signals fromdownstream flow meters 128 and 130 channeled to controller 124 thatcontrols the position of the valve elements, for example, but notlimited to, pintle and poppet valves positioned within integratedejector valve assemblies 106 and 108.

As described above if bleed air pressure is assumed to be maintainedbetween 30 and 40 psig. A pressure range setting of, for example, 32±2psig may be selected for HP operation and a pressure range setting of,for example, 38±2 psig may be selected for LP operation. Whenever bleedsystem pressure is above the HP setpoint, the HP pintle valve will befully closed. Whenever the pressure is below the LP setpoint, the LPpoppet valve will be fully open. Whenever the pressure is above the LPsetpoint the poppet valve will be fully closed to prevent backflow fromHP bleed port 120 or 122 to LP bleed port 110 or 112, respectively.

Consider first the operation of one side as HP and LP pressureregulators. At rest, a first spring 230 keeps first valve assembly 200closed. Second valve assembly 208 is held closed by a second spring 232having sufficient force to keep the unpowered second valve assembly 208closed at maximum downstream duct pressure to prevent backflow andassure shut-off. The unpowered torque motor servo valve 223 directs HPbleed air to chambers 216 and 218, keeping first valve assembly 200 andsecond valve assembly 208 closed during engine start.

When the engine is running and the bleed air system is actuated, boththe LP and HP flow control circuits are actuated initially when thebleed air system pressure is low. HP air aspirates LP air via ejector222.

As bleed air pressure rises above 32 psi, second valve assembly 208slowly closes. If pressure continues to rise, indicating that there issufficient pressure from the LP duct to supply the bleed air needs,second valve assembly 208 will close fully and the system will besupplied only from LP air regulating at 38 psi. A large demand, such asactuation of the wing anti-ice system, causes system pressure to drop.If there is insufficient LP bleed capability to maintain 38 psi at thishigher flow then the pressure will continue to fall until it drops intothe HP pintle valve operating range. The pintle valve slowly opens,aspirating LP air to mix with the HP air. The pintle valve continues toopen until the pressure reaches 32 psi.

If LP pressure falls so low that aspiration ceases, there will be noflow from LP bleed port 110 and no flow forces maintaining first valvemember 206 open, so first valve member 206 will close, acting as a checkvalve to prevent backflow.

When LP pressure rises above 32 psi, the ΔP across first valve member206 will cause first valve member 206 to open, restoring flow from LPbleed port 110. This flow may cause the pressure to rise above the HPsetpoint of 32 psi in which case second valve assembly 208 will close,or it may maintain an intermediate position to supply part of the totalflow, assisted by ejector 222.

During operation using a two engine aircraft, where each engine isequipped with an integrated ejector valve assembly 106 or 108 operatingindependently to maintain a common downstream bleed system pressure,controller 124 also acts to balance the left and right engine flows.

As before, second valve assemblies 208 attempt to maintain 32 psi at anoutlet of their respective integrated ejector valve assemblies 106 or108 and first valve assemblies 200 attempt to maintain 38 psi at theoutlet of their respective integrated ejector valve assemblies 106 or108. At the same time, controller 124 monitors the flow through eachcircuit 105 and 107. If the flow through one circuit is greater than theflow through the other circuit, controller 124 transmits a signal tobias the associated first valve assembly 200 and second valve assembly208 more closed. This bias signal is gradually increased until the leftand right engine flows are approximately equal. This flow balancing isintended to respond slower than the pressure control function but ispersistent and continuous so that after pressure transients, the flowsare again rebalanced.

A single bleed system pressure signal is used by controller 124 tocontrol all pressure and flow regulation functions. This signal may bean average of two or more pressure sensors or three sensors may vote toeliminate a failed sensor. A single composite signal is used so that anypressure drift affects both sides and all pressure equally.

To facilitate system pressure stability first valve assembly 200 actingas the LP pressure regulator is configured to respond relatively fast,second valve assembly 208 acting as the HP pressure regulator isconfigured to respond slower, and the flow balancing bias is configuredto respond slowest.

FIG. 3 is an isometric cross section of integrated ejector valveassembly 106 (shown in FIG. 1) in accordance with an exemplaryembodiment of the present invention. Alternative embodiments of thepresent invention include positioning a check valve upstream of secondvalve assembly 208 and removing poppet return spring 230. In variousembodiments, the poppet end or pintle end may have a conicalcross-section, a spherical cross-section, or a contoured cross-section.One or both valve elements can be actuated with pneumatic pressuredirectly from a pneumatic reference regulator, avoiding the need for anelectronic controller. The bleed air control functions accomplished in asingle integrated ejector valve assembly include shut-off of HP and LPbleed air, LP check valve to prevent backflow of HP air, bleed airpressure regulation in both HP and LP bleed extraction modes, flowbalancing between left and right engines, preferential use of LP bleedair whenever sufficient LP bleed pressure is available, and aspirationof LP air with HP air via an ejector to extract LP bleed air when the LPpressure is marginal.

The term processor, as used herein, refers to central processing units,microprocessors, microcontrollers, reduced instruction set circuits(RISC), application specific integrated circuits (ASIC), logic circuits,and any other circuit or processor capable of executing the functionsdescribed herein.

As used herein, the terms “software” and “firmware” are interchangeable,and include any computer program stored in memory for execution byprocessor 126, including RAM memory, ROM memory, EPROM memory, EEPROMmemory, and non-volatile RAM (NVRAM) memory. The above memory types areexemplary only, and are thus not limiting as to the types of memoryusable for storage of a computer program.

As will be appreciated based on the foregoing specification, theabove-described embodiments of the disclosure may be implemented usingcomputer programming or engineering techniques including computersoftware, firmware, hardware or any combination or subset thereof,wherein the technical effect is controlling a bias of the integratedejector valve assembly based on an output flow to match the flows usingLP bleed air and if needed HP bleed air. Any such resulting program,having computer-readable code means, may be embodied or provided withinone or more computer-readable media, thereby making a computer programproduct, i.e., an article of manufacture, according to the discussedembodiments of the disclosure. The computer-readable media may be, forexample, but is not limited to, a fixed (hard) drive, diskette, opticaldisk, magnetic tape, semiconductor memory such as read-only memory(ROM), and/or any transmitting/receiving medium such as the Internet orother communication network or link. The article of manufacturecontaining the computer code may be made and/or used by executing thecode directly from one medium, by copying the code from one medium toanother medium, or by transmitting the code over a network.

The above-described embodiments of a method and system of supplyingbleed air using a single housing integrated low pressure (LP) and highpressure (HP) integrated ejector valve assembly provides acost-effective and reliable means for supplying bleed air to anaircraft. The integrated ejector valve assembly incorporates an LPregulator assembly, HP regulator assembly, ejector, and shut-off valvemembers in a single housing providing a simpler assembly having fewerparts and reduced weight. Simplicity provides both higher reliabilityand lower manufacturing cost. Low weight is always on advantage onaircraft equipment. As a result, the methods and systems describedherein facilitate operation and maintenance activities associated withaircraft in a cost-effective and reliable manner.

This written description uses examples to disclose the invention,including the best mode, and also to enable any person skilled in theart to practice the invention, including making and using any devices orsystems and performing any incorporated methods. The patentable scope ofthe invention is defined by the claims, and may include other examplesthat occur to those skilled in the art. Such other examples are intendedto be within the scope of the claims if they have structural elementsthat do not differ from the literal language of the claims, or if theyinclude equivalent structural elements with insubstantial differencesfrom the literal languages of the claims.

The invention claimed is:
 1. A method of supplying engine bleed air to an aircraft using a first integrated ejector valve assembly, said method comprising: controlling a flow of a relatively lower pressure fluid received at the first integrated ejector valve assembly using a first valve assembly; controlling a flow of a relatively higher pressure fluid received at the first integrated ejector valve assembly using a second valve assembly; maintaining a pressure in an outlet of the first integrated ejector valve assembly using the controlled flow of relatively lower pressure fluid and the controlled flow of relatively higher pressure fluid; biasing at least one of the first valve assembly and the second valve assembly based on the outlet flow from the first integrated ejector valve assembly; and supplying a portion of the engine bleed air to an aircraft using a second integrated ejector valve assembly.
 2. A method in accordance with claim 1, further comprising receiving at least one of the flow of the relatively lower pressure fluid and the flow of the relatively higher pressure fluid from a bleed port on a gas turbine engine.
 3. A method in accordance with claim 1, wherein controlling a flow of a relatively lower pressure fluid further comprises aspirating the flow of relatively lower pressure fluid through an ejector positioned within the first integrated ejector valve assembly using the flow of relatively higher pressure fluid.
 4. A method in accordance with claim 1, further comprising coupling an outlet of a second integrated ejector valve assembly to an outlet of the first integrated ejector valve assembly.
 5. A method in accordance with claim 1, wherein supplying engine bleed air to an aircraft comprises: supplying engine bleed air to an aircraft using the first integrated ejector valve assembly to supply a first portion of the engine bleed air and a second integrated ejector valve assembly to supply a second portion of the engine bleed air; measuring the flow of the first portion and the flow of the second portion; and adjusting the flow of at least one of the first portion and the second portion such that the flow of the first portion and the second portion are substantially equal.
 6. An aircraft system comprising: a first gas turbine engine comprising a first high pressure bleed port and a first low pressure bleed port; a second gas turbine engine comprising a second high pressure bleed port and a second low pressure bleed port; an engine bleed air header configured to channel bleed air at a selectable pressure to the aircraft; a first integrated ejector valve assembly coupled in flow communication between said first high pressure bleed port and first low pressure bleed port, and said engine bleed air header; a second integrated ejector valve assembly coupled in flow communication between said second high pressure bleed port and second low pressure bleed port, and said engine bleed air header; and a controller communicatively coupled to said first integrated ejector valve assembly and said second integrated ejector valve assembly, said controller configured to substantially match an output flow of said first integrated ejector valve assembly and said second integrated ejector valve assembly.
 7. A system in accordance with claim 6 wherein at least one of said first integrated ejector valve assembly and said second integrated ejector valve assembly includes a first valve assembly configured to maintain a pressure at said engine bleed air header greater than a first predetermined range of pressure and a second valve assembly configured to maintain the pressure at said engine bleed air header greater than a second predetermined range of pressure, wherein the first range of pressure is greater than the second range of pressure, and wherein the first and second ranges do not overlap.
 8. A system in accordance with claim 6 wherein at least one of said first integrated ejector valve assembly and said second integrated ejector valve assembly includes a bias assembly configured to receive a bias command from said controller, the at least one of said first integrated ejector valve assembly and said second integrated ejector valve assembly configured to adjust the output flow of a respective one of at least one of said first integrated ejector valve assembly and said second integrated ejector valve assembly using the bias command.
 9. A system in accordance with claim 6 wherein at least one of said first integrated ejector valve assembly and said second integrated ejector valve assembly includes a bias assembly configured to receive a bias command from said controller, the at least one of said first integrated ejector valve assembly and said second integrated ejector valve assembly configured to adjust the output flow of a respective one of at least one of said first integrated ejector valve assembly and said second integrated ejector valve assembly using at least one of an associated first valve assembly and a second valve assembly positioned within said integrated ejector valve assembly.
 10. A system in accordance with claim 9 wherein said bias assembly comprises a bias member configured to bias said first valve assembly and said second valve assembly to a closed position.
 11. A system in accordance with claim 6 wherein said bias assembly comprises at least one of an electrical and a pneumatic positioning assembly. 